RAS question
Laterite soils are found mainly on:
Correct answer: (A) High plateaus in heavy rainfall regions.
Laterite soils are found mainly on high plateaus in heavy-rainfall regions, where intense leaching under wet-dry tropical conditions makes them acidic and nutrient-poor.
Explanation
Laterite soil forms in tropical and subtropical regions with alternating wet and dry seasons. Heavy rainfall causes intense leaching, washing soluble material out of the soil. NCERT describes lateritic soils as deep to very deep, acidic and generally deficient in plant nutrients. In India, they occur mainly in the Western Ghats, plateau areas of the Eastern Ghats, the southern states, Odisha, parts of West Bengal and parts of North-east India. Thus, the question's cue—heavy rainfall on high plateaus—fits laterite; the other terrains represent different soil environments.
Why the other options are wrong
- (B) Desert margins indicate arid soil conditions, whereas laterite needs heavy rainfall and intense leaching.
- (C) Mountain tops above 5000 m are associated with snow-covered conditions rather than the high-rainfall plateau setting in which laterite forms.
- (D) River flood plains are the setting for alluvial soil, not laterite soil formed by leaching in heavy-rainfall plateau areas.
Concept
This tests the Indian geography concept of soil distribution by climate, relief and leaching. It recurs in RAS because soil-type questions often require matching a soil with its formation process and region, not just memorising its name.